SMIL is a multimedia control language defined by World Wide Web Consortium (W3C) for encoding time based multimedia presentation delivered over the Web, defining when, where and how to play segments of multimedia (such as animation, audio, video, still image, static text and text stream). With such a language, a set of independent multimedia objects can be integrated into synchronized multimedia contents, and user interaction can be supported during playing, SMIL may be applied in Web TV, on-line course, multimedia presentation, etc. SMIL has been widely used in client side applications by Realnetwork, Apple, Microsoft, etc.
Conventional SMIL browsers, such as Xsmiles, Apple QuickTime and Helix, can support full profile and extension of SMIL 2.0. These browsers, similar to Web browsers, are pure client software designed for PC-like multimedia devices.
With the advent of more and more networked PvC devices, such as Personal Digital Assistant (PDA), mobile phone, in-home and telematix device, the requirement is arisen to play SMIL based multimedia contents on such devices. However, a PvC device usually can only play media objects in one kind of media format due to the limitation of media objects playable on such device, so it is difficult for one PvC device to support the playing of a plurality of media objects. For instance, a POTS telephone only supports audio; an IP telephone and a mobile phone may support audio and simple text input; a PDA may support text and still image, and even simple video stream, based on network browsing and user interaction; and a TV set and digital HiFi system support the playing of real-time video and audio stream. However, the resources of the PvC devices for the playing media objects as described above are limited so that only a subset of standard multimedia types defined by SMIL can be played. Besides, the limitation of resources makes it difficult to implement such functions as multi-threading and complicated timing/synchronization mechanism and integration of a plurality of media on PvC devices.
There are prior methods for supporting SMIL on handheld devices. For instance, a 3GPP SMIL profile used for Multimedia Messaging Service (MMS) may support the playing of SMIL based multimedia contents on a mobile phone with SMIL interpretation capability. A 3GPP SMIL profile, however, is only a subset of SMIL 2.0 basic profile and the media contents that may be played on a handheld device are limited. For instance, US Patent Application 2003/0229847 entitled as “Multimedia Reproducing Apparatus and Method” discloses a method for reproducing SMIL based multimedia contents on a single mobile device. But, the application focuses on serialization of the parallel timing and synchronization mechanism, and does not solve the vital problem of resources for playing complicated multimedia contents and flexible user interaction. Thus, both above-mentioned approaches can only support the playing of SMIL based multimedia contents on PvC devices with SMIL interpretation capability. As a result, it is impossible to play SMIL based multimedia contents on PvC devices without SMIL interpretation capability.